Former professional American football players die from brain-wasting diseases at markedly higher rates than the general male population, according to a large new study, adding some of the clearest population-level evidence yet to long-running concerns about the sport and the brain. The researchers found former NFL players were roughly four times as likely to die from a neurodegenerative disease, and far more so if they died young.
What the study found
The analysis, carried out by researchers at Mass General Brigham, Boston University and a concussion-focused foundation, examined death records for nearly 20,000 men who played in the NFL over several decades, using data from the US Centers for Disease Control and Prevention, ESPN reported. Across the group, deaths from neurodegenerative diseases, a category that includes Alzheimer's, Parkinson's, ALS and other conditions, occurred at about four times the expected rate. For players who died before the age of 60, the study found the risk was many times higher still.
The likely explanation
The researchers linked the pattern to the repeated blows to the head that are routine in football and to chronic traumatic encephalopathy, or CTE, a degenerative brain condition associated with such impacts. One of the study's authors described the results as the clearest evidence to date that former players are dying of these diseases at genuinely, and measurably, higher rates. Notably, the study found the former players did not have higher death rates from causes like cancer or heart disease, and in some cases lower ones, which the researchers said pointed to something specific about the brain rather than a general effect of an athletic career.
The important caveats
The findings come with real limits, which the researchers stressed. Death-certificate data is not perfect, and the study cannot prove that CTE, or football, caused any particular person's death; neurodegenerative diseases have multiple contributing factors, including age and genetics. CTE itself can currently only be diagnosed with certainty after death, by examining the brain. So the study establishes a strong statistical association, not a verdict on any individual case, and it looks at players from past eras, not necessarily today's game with its changed rules and protocols.
The context
The results land in a debate that has shadowed football for years, over how much the sport damages the brain and what leagues owe the people who play it. The NFL, which has faced lawsuits and scrutiny over its handling of head injuries and has changed some rules and concussion procedures, had not issued an immediate response to the study. For players and families, the research is less an abstraction than a confirmation of fears many already held. It does not settle every question, but it sharpens the central one: what the accumulated hits of a football career do to the brain, over a lifetime, and how much of that risk can be reduced.
